DBIx::Class features a fully featured compatibility layer with Class::DBI and some common plugins to ease transition for existing CDBI users.

This is not a wrapper or subclass of DBIx::Class but rather a series of plugins. The result being that even though you're using the Class::DBI emulation layer you are still getting DBIx::Class objects. You can use all DBIx::Class features and methods via CDBICompat. This allows you to take advantage of DBIx::Class features without having to rewrite your CDBI code.

Relationships between tables (has_a, has_many...) must be declared after all tables in the relationship have been declared. Thus the usual CDBI idiom of declaring columns and relationships for each class together will not work. They must instead be done like so:

package Foo;
use base qw(Class::DBI);
Foo->table("foo");
Foo->columns( All => qw(this that bar) );
package Bar;
use base qw(Class::DBI);
Bar->table("bar");
Bar->columns( All => qw(up down) );
# Now that Foo and Bar are declared it is safe to declare a
# relationship between them
Foo->has_a( bar => "Bar" );